Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Quantas rodadas Shirley van der Lof participou?
 ###Tabelas: CREATE TABLE teams_and_drivers (teams_and_drivers_id AUTO_INCREMENT PRIMARY KEY, Team VARCHAR, Driver VARCHAR, Class VARCHAR, Chassis VARCHAR, Engine VARCHAR, Rounds VARCHAR) CREATE TABLE pga_tour_career_summary (pga_tour_career_summary_id AUTO_INCREMENT PRIMARY KEY, Year INT, Starts INT, Wins (Majors) VARCHAR, 2nd INT, 3rd INT, Earnings ($) INT, Money list rank VARCHAR, Scoring average VARCHAR) CREATE TABLE ties (ties_id AUTO_INCREMENT PRIMARY KEY, Tie no INT, Home team VARCHAR, Score VARCHAR, Away team VARCHAR, Attendance INT) CREATE TABLE round_8_national_day_round (round_8_national_day_round_id AUTO_INCREMENT PRIMARY KEY, Home team VARCHAR, Home team score VARCHAR, Away team VARCHAR, Away team score VARCHAR, Venue VARCHAR, Crowd INT, Date VARCHAR) CREATE TABLE 2009_draft_picks (2009_draft_picks_id AUTO_INCREMENT PRIMARY KEY, Round INT, Overall VARCHAR, Player VARCHAR, Position VARCHAR, Nationality VARCHAR, Club team VARCHAR)  
SELECT Rounds FROM teams_and_drivers WHERE Driver = shirley van der lof